The present invention relates to a battery case for receiving batteries used as a power source for portable data input processors such as portable terminal devices and the like.
Such portable terminal devices generally use as a power source a storage battery. An example of conventional terminal devices provided with a storage battery is described below with reference to FIG. 1.
As shown in FIG. 1, a portable terminal device body (referred to as "body" hereinafter) 51 has a recessed portion 52 formed therein. Engaging holes 54 are formed at both ends of one short side 53 in the recessed portion 52, and minus terminals 56 and two plus terminals 57 are provided at both ends of the other short side 55 in the recessed portion 52. The body 51 has a connecting recessed portion 58 formed at the opening-side end of the recessed portion 52 on the side of the short side 55 thereof, and a screw hole 59 formed at the center of the bottom of the connecting recessed portion 58.
On the other hand, a storage battery 60 has engaging protrusions 63 provided at both ends of one short side 62 of a case 61 and a minus external terminal 65 and a plus external terminal 66 both cf which are connected to secondary batteries (not shown) contained in the case 61 and which are provided at both ends of the other short side 64. The case 61 has a connecting protrusion 67 which is provided at the external side edge of the short side 64 and an attaching screw 68 which is supported by being passed through a screw through hole of the connecting protrusion 67.
The operation of attaching the battery 60 in the above arrangement is described below.
The engaging protrusion 63 of the case 61 is first engaged with the engaging hole 54 on the side of the body 51. The case 61 is then rotated around the engagement portion serving as a fulcrum so as to be accommodated in the recessed portion 52 on the side of the body 51, and the connecting protrusion 67 is engaged with the connecting recessed portion 58. This brings about the contact of the minus and the plus external terminals 65 and 66 of the storage battery 60 with the minus and plus external terminals 56 and 57 on the side of the body 51. The attaching screw 68 supported by the screw through hole of the connecting protrusion 67 on the side of the storage battery 60 is then screwed into the screw hole 59 on the side of the body 51 so that the storage battery 60 can be attached to the body 51.
Conversely, the attaching screw 68 is loosened, and the case 61 is rotated around the engagement portion between the engaging protrusion 63 and the engaging hole 54, which portion serves as a fulcrum, so that the connecting protrusion 67 of the storage battery 60 is separated from the recessed portion 52 on the side of the body 51. The engaging protrusion 63 is then separated from the engaging hole 54 so that the storage battery 60 can be separated from the body 51.
There have recently been demands for the possibility of selective use, as a power source for a portable terminal device, of the above storage battery or a single-cell primary battery such as an alkali battery for the purpose of increasing the capacity and decreasing the weight of the device. There have also been demands for the possibility of selective use of a storage battery when a primary battery is used as a power source and the possibility of selective use of different types of nickel-hydrogen batteries or batteries such as lithium secondary batteries or the like, which are newly developed and have new characteristics, other than the alkali battery. However, the battery used as a power source for the conventional portable terminal device is limited to a storage battery or a primary battery.